title: The substrate-associated protein p45 of porcine endothelial cells: multiple isoforms, cytoskeletal-like properties and induction by hyperoxic stress.
abstract: 1. Cultured mesenchymal cells respond to hyperoxic (hyper-O2) stress with increased cell flattening/substrate adhesion and overall 47-69% reductions in total matrix-associated (i.e. saponin-resistant [SAP fraction]) protein. 2. Electrophoretic analysis revealed a selective hyper-O2-related 2.7- to 4-fold increase in SAP and cytoskeletal fraction deposition of the protein p45 beginning early (within 12 hr) after initial exposure of porcine endothelial cells to hyper-O2 and increasing over a 48 hr period. 3. p45 consisted of 8 distinct isoforms differing only in pI; hyper-O2-augmented matrix deposition of 3. p45 consisted of 8 distinct isoforms differing only in pI; hyper-02-augmented matrix deposition of p45 involved all 8 isoforms with the more basic subtypes exhibiting slightly greater net increases. 4. Both the specificity and time course of p45 induction, relative to the onset of hyper-O2 cytoarchitectural remodeling, indicate that p45 up-regulation constitutes an early aspect of the hyper-O2 adaptive response.
authors.affiliation: Laboratory of Nuclear Hematology, Department of Veterans Affairs Medical Center, Albany, N.Y. 12208.
authors.forename: J E
authors.initials: JE
authors.lastname: White
authors.forename: M F
authors.initials: MF
authors.lastname: Tsan
authors.forename: P G
authors.initials: PG
authors.lastname: Phillips
authors.forename: P J
authors.initials: PJ
authors.lastname: Higgins
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002417:Cattle; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism*; D008970:Molecular Weight; D010100:Oxygen / Q000494:pharmacology*; D011499:Protein Processing, Post-Translational; D011506:Proteins / Q000378:metabolism; D011651:Pulmonary Artery; D051381:Rats; D012503:Saponins / Q000494:pharmacology; D013552:Swine; D014746:Vimentin / Q000378:metabolism
chemical_list: D000199:Actins; D003598:Cytoskeletal Proteins; D006023:Glycoproteins; D011506:Proteins; D012503:Saponins; D014746:Vimentin; D010100:Oxygen